FxGen

I wrote a new operator called Lookup. It has two inputs, a texture and a bitmap which contains texture coordinates U,V packed into the R and the G channel (B is not used). The output texture has the same size as the texture coordinate bitmap and the colors are looked up in the texture (which can be of arbitrary size).

It can be used for creating some nice marble and wood textures.
I have attached an image showing a cloud colored with a 1D color fade.


IMPLEMENT_CLASS(NLookupOp, NOperator);

NLookupOp::NLookupOp()
{
}

udword NLookupOp::Process(float _ftime, NOperator** _pOpsInts)
{
//Two inputs (texture, texcoords)
if (m_byInputs!=2) return (udword)-1;

//Get input Texture and TexCoords
NBitmap* pSrc = (NBitmap*)(*(_pOpsInts+0))->m_pObj;
NBitmap* pTexCoords = (NBitmap*)(*(_pOpsInts+1))->m_pObj;

udword w = pTexCoords->GetWidth();
udword h = pTexCoords->GetHeight();
udword tw = pSrc->GetWidth();
udword th = pSrc->GetHeight();

float scaleW = tw / 256.0f;
float scaleH = th / 256.0f;

//Bitmap instance
gNFxGen_GetEngine()->GetBitmap(&m_pObj);

//Set Texture size
NBitmap* pDst = (NBitmap*)m_pObj;
pDst->SetSize(w, h);

/////////////////////////////////////////
//Process operator
RGBA* pPxTexCoords = pTexCoords->GetPixels();
RGBA* pPxSrc = pSrc->GetPixels();
RGBA* pPxDst = pDst->GetPixels();

for (udword y=0; y < h; y++)
{
for (udword x=0; x < w; x++)
{
udword u = pPxTexCoords->r * scaleW;
udword v = pPxTexCoords->g * scaleH;
pPxTexCoords++;

*pPxDst++ = pPxSrc[(v*tw) + u];
}
}
return 0;
}